This invention relates in general to weaving and more particularly to a loom for producing three dimensional weaves.
Three dimensional weaves, in contrast to conventional two dimensional weaves which are most commonly associated with fabrics, have substantial thickness by reason of the fact that the yarns or strands which make up the weave extend in three directions. Comparing the weave with a cartesian coordinate system, some of the yarns extend in the X direction, more of the yarns extend in the Y direction, and still more extend in the Z direction. The individual strands of Y and Z yarns are woven through the parallel strands X yarns, thus creating the weave. more
These weaves when impregnated with suitable resins or graphitic materials produce extremely light weight and strong composite structures which are useful in the aero-space industry as well as others. Moreover, when the yarns are of the ablative variety, such as high modulus carbon or graphite, the composite structure is capable of withstanding extremely high temperatures.
Heretofore, three dimensional weaves have been produced, but the procedures for creating such weaves have been almost entirely manual operations. As a result, they are extremely tedious and time-consuming. One procedure involves pushing hollow needles through stacked layers of previously woven cloth and inserting yarn of the third direction through these needles. From a practical standpoint, the needle cannot be over about 18 inches in length, and as a result, the process is not suitable for producing woven configurations of substantial length. Furthermore, current weaving procedures require making rather sharp bends in the yarns as they are woven together. However, ablative yarns break relatively easily when sharply bent, and this substantially increases the time and difficulty of the process.